1. Field of the Invention
This invention relates to improvements in sphere launching and sphere receiving apparatus and more particularly, but not by way of limitation, to a single valve which may be utilized for both a launching operation or a receiving operation.
2. Description of the Prior Art
Pipelines are in widespread use today for delivering or transporting fluid products from site to site, such as gas and oil products from an oil well site to a handling plant. The movement of many products through the line, and particularly natural gas, presents many problems, and one particularly difficult problem is the handling of the condensation in the pipeline as the gas stream flows therethrough. The condensation collects in each of hundreds of sags inherent in a pipeline crossing a rolling countryside. The gasoline of fluid contained within each sag becomes an impediment to the flow of the gas stream through the pipeline. In order to move this condensate through the pipeline, it has become increasingly desirable to move a spheroid, or pipeline pig, through the pipeline to force the condensate therethrough. The pig is normally propelled through the pipeline by the pressure of the gas stream itself, and has proven to be an expedient means for solving the problem.
A pipeline usually comprises a plurality of progressively larger or smaller diameter pipe sections, and it is desirable to inject a pig or spheroid at multiple intervals along the pipeline in accordance with the diameter variances therein. Thus, it is necessary to provide apparatus for launching of the sphereoids at spaced intervals along the pipeline, as well as apparatus for receiving the previously injected sphereoids. In addition, the pipeline extends through long distances over the countryside or open spaces and is frequently unattended, and it is desirable to provide an automatic launching means at the desired intervals along the pipeline for injecting the spheroids into the interior thereof.
Many devices, such as that shown in the H. N. Eagleton Pat. Nos. 3,166,094, issued Jan. 19, 1965, and entitled "Receiving Valve," and 3,169,263, issued Feb. 16, 1965, and entitled "Sphere Launching Apparatus" have been developed for the injecting and removing of spheres from the pipeline, but these devices have certain disadvantages in that completely different and distinct valves must be provided for the two functions, and in addition, the devices are somewhat complicated and expensive in use and construction.